In a vehicle to vehicle (V2V, Vechicle to Vechicle) communications system, any vehicle may exchange data with a surrounding vehicle in a broadcast or unicast manner. A device sends a V2V signal in the broadcast manner, so as to efficiently transfer a signal and improve network flexibility. The V2V signal is a periodic broadcast signal, and includes vehicle status information such as a vehicle identifier, location information, a speed, an acceleration, or a running route.
In the V2V communications system, a vehicle sends a periodic signal of the vehicle according to a transmission pattern, and receives a periodic signal sent by another vehicle, so that vehicles can find each other. In a vehicle running process, a vehicle in a region may suddenly change a running direction or speed because of various environment factors, human factors, or the like, and therefore, may collide with another vehicle in a specific physical distance in a specific time, causing an accident.
To resolve the foregoing problem, in the prior art, a reference vehicle receives a periodic signal from another vehicle, and determines information such as a location or a speed of a surrounding vehicle. When the reference vehicle suddenly changes a running direction or a speed because of various environment factors, human factors, or the like, the reference vehicle sends a signal to a surrounding target vehicle in a relatively short time, for example, a vehicle that may collide with the reference vehicle. The signal is a notification signal of a relatively high priority, for example, an alarm (FCW, Forward collision Warning) signal. Therefore, the vehicle that may collide with the reference vehicle performs a corresponding action (such as emergently brakes, changes a running direction, or decreases a running speed) after receiving the FCW signal, so as to reduce a collision probability of the vehicle that may collide with the reference vehicle, and reduce a traffic accident.
However, in the prior art, the vehicle that may collide with the reference vehicle knows neither a time at which the reference vehicle sends the notification signal of a high priority, for example, an FCW signal, nor a resource on which the signal can be received. Consequently, the target vehicle, for example, the vehicle that may collide with the reference vehicle has a relatively long delay in receiving the notification signal of a high priority, or even cannot receive the signal. This method is not reliable.